1. Field of the Invention
The present invention relates to a means and methods for elevating structures, and in particular, to poles anchored in the ground for vertically elevating any type of member or members to an extended distance.
This invention further relates to installation of lighting fixtures in a position elevated above the ground on poles, and in particular, the comprehensive integrated combination of fixture supports and poles, wiring, and electrical components to operate the lighting fixtures.
2. Problems in the Art
A number of structures or things must be suspended from the ground. Examples are light fixtures, sirens, antennas, wires, and the like. Many times these structures need to be rigidly supported. Of course, a conventional means to accomplish this is to utilize an elongated pole.
Commonly known examples of poles of this type are telephone poles, electrical wire poles, light poles, sign poles, and utility poles. Most of these types of poles are anchored in the ground and extend vertically upward to many times tens of feet in height.
The widespread utilization of these types of poles is indicative of the preference to utilize elongated structures or poles to elevate objects in the air. For whatever reasons, whether it be economical or practical, the demand for the poles is very high for a number of different uses.
Poles of this nature can be made of a number of materials and can be erected and installed in a number of ways. While each of the commonly used poles achieves the end result of elevating objects in the air, the different types commonly used have both their advantages and disadvantages.
Wood poles represent the longest used and still today the many times preferred type of pole. They are relatively inexpensive, have a good height to diameter strength ratio, and can be rather easily adapted for a number of uses.
Problems and disadvantages of wood poles, however, are at least:
a. Difficult to find straight wood poles, especially for taller heights;
b. Natural processes decay or at least weaken wood;
c. Wood is fairly heavy;
d. Pole comes in single long length which can be difficult to transport;
e. Environmental problems associated with using trees could effect availability;
f. Appearance;
g. Uncertainty of strength;
h. Bottom end is buried in the ground and therefore even more susceptible to decay and deterioration; and
i. Difficulties in providing adequate foundation and support for the pole.
Wood, therefore, may represent a cheaper, more available source for at least shorter poles, but is not the preferred type of pole because of, in significant part, some of the above mentioned problems.
An alternative pole that has more recently been utilized is one made substantially of concrete. For even significantly tall poles, concrete has great strength in compression and with a steel cable infra structure offers strength in tension. With advances in the nature of concrete, such poles offer a relatively economical and very strong alternative to wood.
Disadvantages of concrete are at least the following, however:
a. Very heavy, even with a hollow core (may not be able to make very long);
b. Require a big crane or other power means to lift them which is expensive;
c. The weight tends to cause them to shift when positioned in the ground;
d. It is somewhat difficult to form holes or otherwise attach structures to such poles; and
e. Such poles present shipping problems due to weight, length, and width.
Again, while concrete poles do provide some advantages, their disadvantages prevent them from being the preferred used type of pole.
These types of above-mentioned deficiencies have resulted in the pole of preference being comprised of a steel pole which is anchored in the ground usually to poured concrete fill. Such a combination allows the use of high strength yet lightweight hollow tube steel for the above ground portion, while utilizing lower cost and high weight concrete as the anchor in the ground. This also aids in installation as the concrete bases can be poured and then the lightweight steel poles mounted thereon.
These advantages do not come without a price however. The disadvantages of this type of pole are at least the following:
a. Most expensive;
b. Concrete and rebar (if used) must be custom designed;
c. Heavy, thick base plate must be welded to the lightweight steel tube;
d. Galvanizing, which is the preferred protective coating, is sensitive to the temperature differences between the thick base and thin tube;
e. Concrete foundations must be accurately constructed on the site according to the custom design;
f. The poles and the concrete fill, and any other hardware many times are required to come from different sources and therefore may not adequately match; and
g. Corrosion problems.
As can be appreciated, the problems with steel and concrete foundation poles are not insignificant. Because the joint between the steel and concrete will have to take much of the stress provided by the long moment arm of the upwardly extending pole, and because of wind load and other factors, it is critical that for each installation the junction between the pole and the foundation be accurately and correctly prepared. This is an intricate matter requiring not only the correct design specifications and construction of the concrete foundation and the steel pole, but also accurate and faithful adherence to design and installation specifications by field personnel in forming the concrete foundation.
The custom design must include not only the height and weight requirements associated with each particular pole, but also must consider the type and strength of concrete used, the design of the rebar cage in the concrete, and the design and placement of hardware attaching the steel pole to the concrete.
As is well understood by those with ordinary skill in the art, a custom design for the concrete foundations requires significant expenditure of resources. Additionally, the success of the design is then entirely dependent upon its implementation in the field.
Unfortunately, a significant and real problem exists in contractors carrying out the installations not doing so accurately. Without a reliable match between the design parameters of the concrete foundation and the parameters associated with the steel pole with its actual installation, the entire pole structure is susceptible to damage or failure. Accordingly, substantial expense may be incurred over designing and installing the concrete foundations to allow for field installation tolerances. Additionally, concrete requires up to 28 days to develop full strength needed for tensile strength and to anchor the bolts used to secure the pole. The compressive qualities of concrete develop more quickly.
A second major problem with steel pole and concrete foundation combinations is that of corrosion. While presently the corrosion problems are addressed by attempting to galvanize all metal components, at least the following impediments exist to that being successful.
The best environment for corrosion is generally within a few feet above and below the ground line. Frequently, concrete and steel poles such as described above have the concrete bases or foundations poured and submerged from close to ground level downwardly. Therefore, the most corrosion-susceptible area of the metal, at or neat the joint with the concrete, is in that area where corrosion is the most likely. Moisture in the form of standing water and condensation is most concentrated in this area. Additionally, this is also an area where the concentration of oxygen is high, which is one of the components of corrosion and rust.
Secondly, as previously mentioned, the joint between the steel pole and the concrete foundation often represents the highest stress area for the combination. It is known in the art that corrosion increases with stress.
Third, the conventional way of securing the joint is to utilize long bolts through a mounting plate of the steel pole into the concrete. These bolts also take a majority of the stress and are therefore very susceptible to corrosion.
Fourth, galvanizing simply cannot be very reliable for the following reasons. Stress is detrimental to galvanization. An annular base plate for the metal pole must be welded to the tubular elongated portion of the pole. For galvanization to be reliable, the surface must be extremely clean. Debris or dirt in general, and in particular flux, which is hard to remove around welded joints, will not take galvanization. Sometimes direct-bury steel poles are utilized. Corrosion problems as well as installation problems similar to described above exist.
Additionally, galvanization is accomplished by heating the metal. For reliable galvanization, the metal must be heated uniformly. However, the baseplate must be made of a much thicker metal than the thin tubular pole on a practical commercial scale. It is almost difficult during a reasonable production time to have a thick-in-cross-section metal portion connected to a thin-in-cross-section metal portion have the same temperature when exposed to heat.
Additionally, the chemical nature of the steel or metal must be known to obtain the correct galvanization result. Heat differences can even crack the weld or otherwise damage the joint or pole. The plate is generally made of a different metal than the pole.
In short, the mounting plate and metal pole must be galvanized inside and out to resist corrosion. For at least the above reasons, it is very difficult to get such a combination correctly galvanized. At a minimum, it is very expensive to do it right. Then, even once galvanized, the high stress in the area is damaging to the galvanization. Another risk is to cracking of the weld because of different thickness of metal.
It can therefore be seen that the conventional types of poles simply have significant and real problems which are detrimental or are disadvantageous. There is a real need in the art for a pole system which does not have these problems.
Additional problems with regard to presently used poles are also significant in the art. One very practical and real problem is involved with the shipping of such poles. For many uses, poles are needed of lengths of thirty, forty, and even up to over 100 feet. While some applications require many poles of similar lengths, and therefore may be sent by rail shipment, where long lengths can probably be accommodated, many applications for such poles require only a relatively small number. To ship such a number by rail is expensive, particularly when many of these applications still require some other type of over-the-highway transportation to the ultimate location.
Generally trucks have a maximum effective carrying length of between 40 and 48 feet, at least, for semi-trailers. However, the effective load carrying length generally is no longer than around 48 feet. Therefore, it is simply not possible to ship poles of much longer length than this via tractor trailer without special and expensive permits.
While attempts have been made to produce concrete poles in segments, this requires significant installation efforts and joints would create risk and problems. Additionally, it must be understood that wood and concrete poles, with their heavy weight, present shipping problems. Even with shipment in tractor trailers, there is a weight limit of approximately 45 thousand pounds, even for the longest semi-trailers. This would limit the number of such poles that could be transported in one truck as some poles, such as concrete, can each weigh several thousand pounds, and even around or over ten-thousand pounds. Additionally, weight permits are required for increasingly heavy loads. Thus, the closer you come to the maximum weight per trailer and truck, the more costs are incurred in obtaining permits and the like for such heavy loads. This is important because optimally the goal would be to have one tractor trailer carry all the poles and parts required for one installation. Because of limit on truck length and load weight limits, concrete and even wood poles have certain limitations.
Still further, for steel poles which are installed with conventional poured concrete foundations, it may be possible to transport the poles in trucks, but a disadvantage is again the requirement that the concrete foundations be created and installed by a local contractor where, in most cases, quality control is less reliable. In other words, the entire combination (pole and foundation) cannot be manufactured and shipped as one unitary shipment and much reliance on a successful installation is with the installer at the site.
It is to be understood that another problem with conventional poles is the difficulty in flexibly and economically creating a base for the pole which will support the pole and prevent tilting of the pole by the number of forces which will be experienced and caused by the pole. For example, a wood pole has its relatively small diameter lower end inserted into the ground. Many times this is insufficient to adequately support the pole because the ground will give way to the variety of forces transmitted down the pole to its base. To prevent this, sometimes a hole larger than the diameter of the wood pole is bored in the ground and then the space between the pole and the walls of the hole are filled with concrete or crushed rock or other backfill. This effectively provides material surrounding the pole which is not easily displaced. It is one way to attempt to effectively increase the diameter of the base of the pole in the ground. To add backfill and to tamp it, or otherwise secure it, requires time, machinery, and effort. It also requires a crane to hold the pole vertically while this is being accomplished, which is also time consuming and expensive.
Steel poles which are attached by bolts to concrete bases in the ground is a way to allow the base to be customized for the type of ground or the forces that the pole will exhibit on the base. However, it is expensive and time consuming to customize a rebar cage and pour the concrete so that it exhibits not only compressive strength but tensile strength. This is needed to provide enough strength at the junction of the pole to the concrete by bolts or other fastening means.
If concrete poles are used, similar problems exist with regard to wood poles. There is therefore a real need in the art for a method to provide a base or foundation for a pole whose effective area can be economically designed, to adopt whatever supporting strength is needed for each situation. Sometimes the base area needs to be large, sometimes it does not need to be so large. There is also a need to keep the base aligned or leveled so that when the pole is attached, the pole will also be in a desired position. It is important to have enough square feet of surface for the base, but also to do it economically.
There is also a problem in the art as to how to optimally utilize the light from a plurality of light fixtures elevated on a pole. Under conventional systems, there is no integrated approach to figuring out what types and how many lighting fixtures are needed for each light pole or combination of light poles, to accomplish a certain lighting criteria. One of the reasons this is not possible is that conventional light pole systems are not very adjustable once the pole is erected. For example, once a wood pole is elevated and concrete or backfill is secured around the base, it cannot be adjusted either vertically, horizontally, or rotationally. A steel pole which is bolted to a concrete base has similar problems. Therefore, much of the adjustment would have to take place by going up to the light fixtures on top of the pole and trying to adjust them.
In essence, there is no way to reliably predict prior to assembly, the exact orientation of the light fixtures, cross arms or supports, and pole, with respect to one another, and with respect to the area which is to be lighted. There is therefore a real need to allow reliability and certainty in these arrangements prior to actual erection of all these components.
Still further, there is a need for the ability to allow the base or foundation of the pole to accurately and reliably predict the position of the top of the pole and light fixtures attached to supporting structure at the top of the pole before it is erected. With such reliable knowledge, the composite lighting system of a plurality of fixtures each on a plurality of poles can be predesigned at the factory, shipped in partially assembled form, and then easily and economically assembled on site. This would allow the significant advantage of avoiding duplication of lighting and most efficiently and economically providing lighting to an area on top of an efficient and economical way of installing the actual poles and bases, and lighting fixtures.
The above rather detailed discussion of conventional poles is set forth to attempt to aid in an understanding of the many factors which are involved in choosing a type of pole, manufacturing it, installing it, and ultimately maintaining it for an extended, economical, and effective useful life. There is no presently satisfactory system which is adaptable to virtually every situation, is flexible in that it can be anchored in all sorts of locations and ground types and all sorts of weather environments, and is useful for all sorts of heights, wind loads, and types of structures to be elevated. For example, steel poles which are secured to concrete bases generally require the base to be fabricated on-site. Rebar cages and concrete must be designed to meet needs of compressive and tensile strength. This takes time and materials. There is a need for a less complicated, quicker system that does not need such reliance on tensile strength of the concrete.
Still further, for purposes of economy, there is a real need for a pole system which can be easily shipped, whether only a few or quite a few; is easy in terms of labor and resources to install; and which can be maintained over a long life span.
Finally, there is a real need for an efficient pole system which allows easy installation and shipment of the entire system together, along with the structure or structures to be elevated and any attendant hardware, such as wiring and the like.
It is therefore a principle object of the present invention to provide a means and method for rigidly elevating a structure which improves over or solves the deficiencies and problems in the art.
Another object of the present invention is to provide a means and method as above described which is generally universal in its application for elevating different structures to different heights for different situations, and with respect to different installations of the base in the ground.
A still further object of the present invention is to provide a means and method as above described which is economical in terms of the manufacture, materials, transportation, installation, labor, and life span.
Another object of the present invention is to provide a means and method as above described which is easy to assemble, install, and maintain.
A still further object of the present invention is to provide a means and method as above described which is durable and strong, both in its individual components and compositely.
Another object of the present invention is to provide a means and method as above described which permits pre-installation design and concurrent shipment of all or most components for each installation.
A further object of the present invention is to provide a means and method as above described which improves corrosion resistance.
Another object of the present invention is to provide a means and method as above described which is an improvement with respect to the problems caused by stress.
Another object of the present invention is to provide a means and method as above described which allows for economical and efficient provision of a supporting base in the ground for a pole, where the base can be easily predesigned and installed for a variety of ground types and pole strength and heights.
A still further object of the present invention is to provide a means and method as above described which facilitates the provision of a composite photometric output from a plurality of light fixtures for each pole, by allowing the fixtures to be quickly and easily aligned to a predetermined position and orientation, and allowing the fixtures to be reliably erected to a position of known and reliable relationship to the target area for the lighting.
As is well known in the art, the conventional way to install elevated lighting fixtures is to transport a pole to the site it will be erected in the ground. Secondly, before erection, some sort of supporting structure such as cross arms are secured to a position near the top of the pole by brackets or otherwise. Third, the lighting fixtures are mounted onto the cross bars by brackets or other means. Fourth, wiring is installed from the light fixtures to electrical components such as ballasts, fuses, and the like. The ballasts and other components also have to be attached to the fixtures, crossbars or pole by brackets or other means. The complete assembly is then erected by a crane and held in position until the portion of the pole in the ground is adequately supported.
The installation process therefore requires a plurality of steps. Some of the steps require different types of expertise. One party might supply and ship the pole. Workers for another contractor may install cross arms and fixtures. Electricians are usually needed for wiring the fixtures to the required components and connection to electrical power.
As can be appreciated, expensive bracket structures are many times needed to construct the cross bars to the top of the pole and to attach light fixtures and wiring at the top of the pole. Sometimes attachment of ballasts (generally at the top of the pole), requires special equipment and efforts.
Additionally, the amount of time needed for the construction of the complete unit is substantial. Each stage of the installation process many times requires various personnel, different completion times, and many times different equipment and supplies. Still further, once the basic components are installed on the pole, the pole must be raised and inserted into the ground or on a base. It must then be held there by a crane until secure, which further prolongs the time and expense of the installation. Once secured, it can not be reoriented or adjusted.
There have been various attempts to address certain of these problems. However, none has comprehensively addressed these concerns and developed an integrated way to produce savings in time, money, and effort.
The inventors Gordin and Drost disclose a pole structure which addresses a portion of the installation of this type of lighting. The base can be accurately secured in the ground with significant savings of time and cost. The pole can be quickly and relatively easily erected on the base with a reduced risk of corrosion problems. If desired, the cross bars can be attached to the pole before erection onto the base. That invention addresses certain problems in the art, such as quicker and easier pole construction. It removes the necessity of installing cross bars and lights once the pole is erected, or at least allows adjustment of the pole once directed onto the base, instead of having to hold the pole while the concrete is setting up or rearranging the cross arms or lights once installed on the cross arms.
The present invention comprehensively addresses all problems involved in lighting installation in the following way. A breakdown of the various concerns for ultimate installation of this type of lighting can be visualized in the following matrix:
Numbers 1-6 list various stages involved with a lighting system from origination to ongoing operation. Letters A-C list the primary structural components of a complete lighting installation.
The boxes 1A-6C of the above matrix are intended to exemplify the many different areas of concern when dealing with lighting applications of the type addressed by the present invention. No single, integrated, approach to all these areas exists in the art. As previously stated, this is extremely significant from the standpoint of the costs in time and money involved with present day methods. Some examples are given below.
With regard to matrix position 1A, resources directed to design of lights tend to be limited to the efficiencies and economies in manufacturing, operation and maintenance of the lights, along with design of how they will functionally operate for certain applications. There is a lack of concern with regard to how the lights will be shipped (matrix box 3A) or how they will be installed (matrix box 4A).
While some design efforts of lights might also be directed towards the electronics associated with the lights (matrix box 1C), there is a noticeable absence of prediction and coordination with the characteristics of poles (matrix boxes 1B-6B) and the total electrical setup with each light and pole (matrix boxes 2C-6C).
By further example, designs of poles are centered on how to make the pole either easy to manufacture (box 2B), or cheap to manufacture and install (boxes 2B, 4B). Minimal concerns are given towards integration with lights or electrical components (boxes 1A-6A, 1C-6C). A major concern is getting the pole in the ground and securing it there. Thereafter, it can require considerable-effort to adjust the lights to a desired orientation, since the pole is nonadjustable.
The primary point of showing the eighteen different matrix positions is to emphasize the complexity of coordinating and integrating all of these factors into an economical yet valuable coordinated lighting installation.
Not only is there an absence of coordinated integration of these factors in the art, additionally there is room for improvement in individual components or methods in the matrix, or sub-components thereof. For example, the design of one light pole may be economical, but it may be less durable than other types, or even less aesthetically pleasing. The structure for fixing the lights to the top of the pole might be easy to manufacture, but extremely difficult and unreliable as far as securement to the pole, accuracy in supporting the lights, or even in the efficiency and economy of the amount of material used.
By still further example, prior art methods of aiming lights once installed in the top of the pole require significant labor. Little consideration is given to the design and manufacturing of the pole structure to reduce the amount of time needed for mounting and aiming the fixtures.
By still further example, because of the separate steps involved in installing a lighting installation, preparation of the electrical components and wiring is usually left until last. It requires electricians and labor to customize the length of the wires, and to install ballast boxes and other components by brackets or other methods to erect a pole and light fixtures. There is an absence of consideration of design and manufacturing to be able to prewire and prepackage all the components necessary for a certain light pole and fixtures at the factory. Still further, there is a noticeable lack in the prior art of being able to design and contemplate the supply or shipping of component parts for several poles, lighting fixtures, and electrical components, to a site by economical and available transportation systems. There is also a lack of contemplation of positioning the components (such as ballast boxes) at a convenient location for future maintenance.
It can therefore be seen that a real need exists in the art for an integrated approach to lighting installations, and that particular components or methods in the prior art also could be improved.
These areas of need for improvement start with the design of lights, pole, and electrical components, and extend all the way to maintenance of the same. An integrated approach looking at all factors of the matrix discussed above is both needed and would be extremely advantageous from an economic point of view, as well as with regard to flexibility and uniformity of lighting installations.
The need of an integrated approach to design (row one of the matrix) would be to design the best lighting fixtures, poles, and electrical components for the application, allow flexibility so that they could be used in different ways and combinations, and provide esthetically pleasing structures; all to provide good function and result for the application. Manufacturing (in row two of the matrix) looks to efficiency and use of materials and expensive labor, along with high reliability, flexibility, and functionality.
Supply (in row three of the matrix) refers to the ability to package and ship all of the components from the factory with high flexibility to minimize the number of different parts that need to be manufactured and the ability to satisfy a variety of different applications.
Installation (in row four of the matrix) demands improved speed with minimization of labor and expensive equipment, but with reliability and accuracy.
Operation (in row five of the matrix) demands simplicity, durability, and reliability, as well as functional advantages.
Finally, maintenance (in row six of the matrix) looks to ease and simplicity of servicing, repair, and replacement of parts.
Some of the prior art addresses individual particulars of the matrix, but none looks at the total integrated picture, or even substantial sections of the matrix.
It is therefore a primary object of the present invention to provide a means and method for integrated lighting fixture supports and components which solves or improves upon the problems and deficiencies in the art.
A further object of the present invention is to provide a means and method as above described which uses an integrated comprehensive approach to all the stages of lighting including design, manufacturing, supply, installation, operation, and maintenance of lighting fixtures, poles, and electrical components to operate the lights.
Another object of the present invention is to provide a means and method as above described which reduces the amount and cost of labor involved in all stages.
Another object of the present invention is to provide a means and method as above described which reduces the cost of all stages.
Another object of the present invention is to provide a means and method as above described which reduces the time involved in all stages.
A still further object of the present invention is to provide a means and method as above described which reduces the possibility of errors in all stages.
Another object of the present invention is to provide a means and method as above described which allows more accurate, reliable, and durable installation.
Another object of the present invention is to provide a means and method as above described which is more efficient and economical in all stages.
A still further object of the present invention is to provide a means and method as above described which is very flexible and adaptable to a variety of different applications.
Another object of the present invention is to provide a means and method as above described which can be utilized on new lighting installations, or in replacement installations.
A still further object of the present invention is to provide a means and method as above described which can be utilized for a variety of different heights of poles, number of lights, and electrical component and power situations.
Another object of the present invention is to provide a means and method as above described which can be substantially predesigned, packaged, and shipped at the factory.
Another object of the present invention is to provide a means and method as above described which can be preassembled to some extent at the factory in a variety of different configurations yet still meet dimension and weight requirements for standardized shipping of components to installation sites.
Another object of the present invention is to provide a means and method as above described which allows the use of an insertable pole top unit on top of a tapered light pole, when the vertical member of the pole top which connects to the tapered pole is modified to have a tapered lower end, where the taper is created from a straight type by flaring the bottom end, as opposed to manufacturing a tapered section.
These and other objects, features, and advantages of the present invention will become more apparent with reference to the accompanying specification and claims.
The present invention relates to means and methods for an improved pole system for rigidly elevating an object or structure in the air with a base anchored in the ground. The invention specifically solves or improves over many of the deficiencies in the prior art by utilizing a special concrete base which is anchored in the ground but to which a lightweight, strong steel pole section or sections can be easily yet reliably secured.
The base includes an upper portion which extends above the ground. The pole has a mating interior bore at its lower end which slip fits over the upper section of the base, but does not get nearer than a few feet from the ground. The upper portion of the base and the interior bore of the pole can either both be tapered in a manner that the pole can be slip fitted a predetermined distance onto the tapered part of the base and secured there, or if the parts are not tapered, have a stop member control how far the pole fits over the base.
Optionally, the pole can be comprised of a plurality of steel sections, each added to the top of the preceding section in turn beginning with the steel section attached to the base in a similar manner by slip fitting each section to the other.
The invention also allows for a base or foundation which can be enlarged economically and efficiently, as needed, to accommodate different types of ground or soil conditions and for different sizes, strengths, and heights of poles. A pretested, prestressed concrete base is positioned and plumbed within a bore in the ground. The bore in the ground is sized according to how much support will be needed. The system relies only on the compressive strength of the concrete, as well as its rigidity when set up to effectively enlarge the size of the base in the ground.
Additionally, the invention allows for a reliable accurate, pre-known positioning of the light fixtures on top of the pole, even though they can be suspended sometimes over 100 feet in the air. The base can be plumbed and set. The pole and pole top, having known, predesigned and reliably consistent relationships, will also end up in pre-defined, pre-known position once the pole is erected on the base. This allows for integration with a three dimensional coordinate system centered on the target area to be lighted. It also allows for a factory pre-design of the number of fixtures, their aiming and orientation, to economize on the number of fixtures needed, and to create a composite efficient beam from each pole that in turn can be integrated with a number of poles for the best possible and most economical lighting.
The invention also allows for the pole top member to be made economically, even though it requires, in some embodiments, a flared lower end to be mated with the flared upper end of the light pole. A straight pipe can be used for the vertical member for the pole top and have its bottom end flared for mating slip fitting on top of the tapered pole. This reduces significantly the cost of the pole top member as opposed to utilizing a tapered center section.
The system therefore provides a strong, almost unitary pole structure which can be adapted to virtually any situation or location. The strength of the base can be designed to accommodate various pole heights and various ground conditions by altering the makeup of the concrete of the base and any reinforcing structure, as to the width of the base, and the length of the base and other factors. The pre-manufactured base can literally be expanded to meet specific strength and support needs by the single step of widening the hole in the ground and pouring concrete around the base as it is held plumb. This effectively expands the area of the base. Also, predefined simple methods of field modifications can be made. In all instances, any metal portions of the pole are kept out of the high corrosion zone near the ground level. Yet, the above ground portion of the system is almost fully comprised of the light weight, yet strong steel. In turn, the base is made of the relatively heavy, stable concrete which cannot corrode.
The invention also relates to the ability of the system to be easily adapted, assembled, and installed. The invention advantageously overcomes the problems associated with installation such as reducing labor costs, material costs, and design costs. It also provides ways to insure installation is reliable such as providing for ways to plumb the base and/or pole segments to insure that the base, and consequently the pole, are plumb after installation.
Still further, the invention overcomes the severe problem in the art of not being able to easily custom design the system of pole structures for each installation and then easily ship, install and maintain those poles.
Additional features and advantages of the invention includes a means and method for an integrated approach to a total lighting installation. Normally, the design, manufacture, and installation of lighting fixtures for lighting installations is quite independent and separate from those same stages with respect to how the lights are elevated and supported, and how the lights are electrically connected to electrical components and an electrical power source. The present invention allows a comprehensive and integrated approach to the design, manufacture, shipment, installation, operation, and maintenance of lighting fixtures, supports and poles, and electrical wiring and components.
A number of different structural features of the invention can be utilized to further this integrated and comprehensive approach. The tapered, slip-fit pole and base described previously can be utilized. A unitary slip-fitable top portion of the pole, with pre-defined relationships between cross arms and the vertical axis of the pole can also be utilized. The manufacturing process can allow the structure to be easily adapted to prewiring and preassembly of light fixtures to the pole top at the factory.
Mounting brackets for ballast boxes to the poles can facilitate quick and easy mounting of the boxes to the pole. Additionally, the ballast boxes themselves are configured at the factory to be almost completely preassembled and prewired. The ballast boxes are actually electrical component enclosures to allow the pre-assembly, prewiring and integration of a number of electrical components beyond just ballasts. With respect to this invention, the term xe2x80x9cballast boxxe2x80x9d will be used interchangeably with xe2x80x9celectrical component enclosurexe2x80x9d. Substantial savings in time and installation costs are achieved by minimizing the amount of work that needs to take place to install and erect the entire lighting installation on site.
The components are manufactured in a manner that they can be easily shipped by convenient, efficient, and economical transportation vehicles. Still further, the components of the entire installation are designed to be able to be selected to meet a variety of desired configurations for different applications. Different pole heights and strengths, different numbers of fixtures, and different wiring and electrical requirements can be easily met without much on-site customization.
Still further, means can be used to increase the durability and reliability of the lighting installation. For example, abrasion and trauma resistant members can be utilized with the wiring extending through the pole to minimize damage or breakage. Strain relief devices can also be utilized to eliminate the risk of damage to the wiring. Specific structure for attachment and communication between components such as ballast boxes and poles is utilized to increase reliability of operation and reduce the risk of water damage or deterioration of the components over time.
The concrete base can be prefabricated. All it requires is some backfill of suitable strength to hold the base against the forces it will experience. Components, such as ballast boxes, can be located at convenient locations for access, once the installation is complete. The pole, generally steel, is upon ground, but near enough the ground to utilize its advantageous properties.
Whether utilized collectively or individually, these enhancements and features represent real savings in time and cost with respect to the installation of lighting structures.